-(x+5)+(x-2)= -x-5+x-2 = -7
2(a-1)-2(3-a)= 2a-2-6+2a = 4a-8
x(x-2)+3(x+1)= x^2-2x+3x+3=x^2+x+3
x^2 to z do kwadratu
